First things first, we need to start the mash fairly logically, and for this you need your calculator and very large pot. You need to heat up some of your treated water, at a rate of 2.8 litres for however many kilograms your ’grain bill’ is. In this case your grain bill (total weight of grains used in the recipe) is 5.75Kg so 5.75 multiplied by 2.8 comes out at 16.1 litres, but as we’re not anal about this, we’ll call it 16 litres. Stick it on the gas cooker and heat it up. Don’t forget to put in your thermometer.
In case you were wondering, ‘Brew Your Own’, the homebrew beer magazine, state that typical homebrewer amounts of water to use for the mash are anywhere in the range of 2.1 to 3.1 litres per kilo of grain. They also go on to say, quite rightly, that you don’t have to know a lot about mash thickness in order to brew good beer. A lot has been written about mash thickness and it’s all on the internet waiting for you. But for now, use 2.8 litres per kilo.
While you’re waiting for your mash water to heat up you should sterilise a jug, your big mixing spoon and your mash tun. When you’ve done that you need to heat up the
tun, and this is done, when your mash water is nearly at the required temperature, by filling up your mash tun with hot water, letting it stand for a few minutes, then pouring away the water. Heating up your mash tun in this way will mean you won’t lose quite so much heat from your mash water when you pour it in.
If a lot has been written about mash thickness, then a whole lot more has been written about mash temperature and the effect it has on your finished beer. But as we’re just starting out, let’s keep it simple for now. There are brewers out there who will tell you they mash at lower and higher temperatures than normal, but a generally accepted range of mash temperatures is 63 to 69°C. Mashing at the lower end of the scale (63 to 66°C) will produce a thin beer, one that has very little body and a thin mouthfeel. Mashing at the higher end (68 to 69°C) will give a very rich beer with a very full body. Mashing at 67°C, straight down the middle, gives you the best of both worlds – a beer that has body, but not too much, and a beer that has a definite mouthfeel which is not over the top. So let’s mash at 67°C…
In order to mash at 67°C you need to heat your mash water up to 75 or 76°C, because you will lose about 8°C in the act of adding and stirring in the grain. Or at least, I do!
Weigh out your pale malt, crystal malt and torrified wheat. Also lay out your mash tun insulation on the floor.
When the mash water is at the required temperature, carefully pour it into the mash tun (making sure the mash tun tap is in the ’off’ position!). 16 litres of water is heavy so jug it out from the big pot rather than risk doing your back in by lifting the pot and attempting to pour it straight into the tun. Pour in to the water the pale malt, crystal malt and torrified wheat. Don't forget to add the treatments, if any, shown by your laboratory report on your water.
Take your spoon and stir the grain; what you’re trying to do here is make sure there are no lumps - smash up the lumps against the side of the tun using your spoon but do it quickly as you don’t want to lose too much heat by turning it into a long drawn out performance.
When you’re satisfied the ‘porridge’ is nice and smooth put the lid on, wrap the insulation around the tun, and hey presto - Congratulations, you’ve just begun your first mash! At this stage, just to avoid any timing mistakes or any doubt, look at your watch and write down the time your mash began and the time it should end (ie. In 90 minutes). For a belt and braces approach I even set the alarm on my phone.
Don’t be fooled into thinking you’ve nothing to do for the next 90 minutes - time to get to work!
After the mash has begun:
1. Weigh out the hops.
2. Sterilise sparging equipment, which is the jug, recirculation sprinkler and sparging jug.
3. Begin heating your sparge water, say, 18 litres or so, to 62°C .
4. Measure how much 25 litres is in your pot - measure from the top of the liquid to the top of the pan, write this down and keep it safe. For instance, I know that when there is roughly 120 millimetres from the top of the liquid to the top of my pan, I have 25 litres in there.
So now you have your first mash under your belt it's time to take a look at the Wort Collecting & Sparging...